Making Predictions with Scatter Plots
Cricket Chirping and Temperature
Crickets make their chirping sound by rapidly sliding one wing cover back and forth over the other. For a long time, naturalists have been aware that there is a linear relationship between temperature and the frequency of the chirps. This implies that if we have a linear equation that describes the chirping – temperature relationship, we can use a cricket as a thermometer.
The precise nature of the chirping – temperature relationship varies from species to species. In the data file cricket.xls, there are 15 chirping – temperature observations for the striped ground cricket (Nemobius fasciatus fasciatus).
Temperature / Chirps per Second88.6 / 20.0
71.6 / 16.0
93.3 / 19.8
84.3 / 18.4
80.6 / 17.1
75.2 / 15.5
69.7 / 14.7
82.0 / 17.1
69.4 / 15.4
83.3 / 16.2
79.6 / 15.0
82.6 / 17.2
80.6 / 16.0
83.5 / 17.0
76.3 / 14.4
1. Create a scatter plot of the data. Use the tools to find the best fit line. Record the equation of the line.
2. Suppose you hear a striped ground cricket at the frequency of 800 chirps / min. What would the temperature be?
3. Suppose you were walking one evening when the temperature was 72°F and you hear a cricket chirping at 12 chirps / sec.
- Is it likely that this is a striped ground cricket? Explain.
- What if you heard 19 chirps / sec?
- What if you heard 15 chirps / sec?
4. At what temperature would you likely hear 0 chirps / sec from the striped ground cricket?
5. Does this relationship hold for all possible temperature values? Over what range do you think the chirping frequency and temperature relationship would be linear? Explain.